Rename CPU count helper function, document its failure case

diff --git a/apps/avifdec.c b/apps/avifdec.c
index 81de197..81df2cb 100644
--- a/apps/avifdec.c
+++ b/apps/avifdec.c

@@ -75,7 +75,7 @@
         } else if (!strcmp(arg, "-j") || !strcmp(arg, "--jobs")) {
             NEXTARG();
             if (!strcmp(arg, "all")) {
-                jobs = avifQueryMaxThreads();
+                jobs = avifQueryCPUCount();
             } else {
                 jobs = atoi(arg);
                 if (jobs < 1) {

diff --git a/apps/avifenc.c b/apps/avifenc.c
index 4415bf8..0ca8ff4 100644
--- a/apps/avifenc.c
+++ b/apps/avifenc.c

@@ -488,7 +488,7 @@
         } else if (!strcmp(arg, "-j") || !strcmp(arg, "--jobs")) {
             NEXTARG();
             if (!strcmp(arg, "all")) {
-                jobs = avifQueryMaxThreads();
+                jobs = avifQueryCPUCount();
             } else {
                 jobs = atoi(arg);
                 if (jobs < 1) {

diff --git a/apps/shared/avifutil.c b/apps/shared/avifutil.c
index 4ddc406..5ae7553 100644
--- a/apps/shared/avifutil.c
+++ b/apps/shared/avifutil.c

@@ -222,7 +222,7 @@
 }
 
 // ---------------------------------------------------------------------------
-// avifQueryMaxThreads (separated into OS implementations)
+// avifQueryCPUCount (separated into OS implementations)
 
 #if defined(_WIN32)
 
@@ -232,7 +232,7 @@
 #pragma warning(disable : 5032)
 #include <windows.h>
 
-int avifQueryMaxThreads(void)
+int avifQueryCPUCount(void)
 {
     int numCPU;
     SYSTEM_INFO sysinfo;
@@ -247,7 +247,7 @@
 
 #include <sys/sysctl.h>
 
-int avifQueryMaxThreads()
+int avifQueryCPUCount()
 {
     int mib[4];
     int numCPU;
@@ -273,7 +273,7 @@
 
 // Emscripten
 
-int avifQueryMaxThreads()
+int avifQueryCPUCount()
 {
     return 1;
 }
@@ -284,7 +284,7 @@
 
 #include <unistd.h>
 
-int avifQueryMaxThreads()
+int avifQueryCPUCount()
 {
     int numCPU = (int)sysconf(_SC_NPROCESSORS_ONLN);
     return (numCPU > 0) ? numCPU : 1;

diff --git a/apps/shared/avifutil.h b/apps/shared/avifutil.h
index 2921cf6..3ea3801 100644
--- a/apps/shared/avifutil.h
+++ b/apps/shared/avifutil.h

@@ -24,7 +24,7 @@
 void avifContainerDump(avifDecoder * decoder);
 void avifPrintVersions(void);
 void avifDumpDiagnostics(const avifDiagnostics * diag);
-int avifQueryMaxThreads(void);
+int avifQueryCPUCount(void); // Returns 1 if it cannot query or fails to query
 
 typedef enum avifAppFileFormat
 {